My friend recently let me copy the ROM data of his CE and now I have a CE emulator, from what I've heard, ICE is very good and I'd like to learn it. Can someone please list the pros and cons of ICE against other languages? Thanks!

First off, I think there is a law against sharing roms like that...
Anyways, ICE has the advantage of being incredibly fast (because it is compiled into ASM/C, rather than parsed on the spot)
At the same time, it is comparable in difficulty to basic. As development progresses, it is getting more and more complete, so it is now not very restrictive when it comes to what it allows you to do.
Basically, you get the speed of asm without the difficulty of asm. It is like some intermediate between the two, with the syntax leaning heavily towards regular basic.

For me, ICE was really easy to learn. You just need a "Basic" foundation.

It should be at least similar to hybrid basic (CSE, and the few ones for the CE), but I don't know how similar. If they are very similar, you'll be good to go! Like mr womp womp said, it's basically a bridge between asm and basic. (a good one, too! )